<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet">
    <script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script>
    <script src="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script>
    <script src="https://unpkg.com/sweetalert/dist/sweetalert.min.js"></script>
</head>
<body>
<form action="" method="post">
    <p>
        username:
        <input type="text" name="username">
    </p>
    <p>
        password:
        <input type="password" name="password">
    </p>
    <input type="submit">
</form>

</body>
</html>